Stefan's Tesla-Pages

My second TTTC (tube type TC)
using up to three russian GU81M tubes

This is one of my future projects, therefore this page is heavily
under construction !

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Table of contents:

1) Specs of the tube[under construction]
2) circuit diagram[under construction]
3) Photos[under construction]
4) results[under construction]

1) Specs of the tube:
[under construction] rated values according
to a data sheet
translated by MD		 rated values according
to the data sheet		 my test para-
meters for the
first shots

final
parameters
(planned)
plate:
max.Anodenspannung (<6 MHz) 3.0 kV 3.0 kV - -
max. Anodendauerstrom 200 mA 200mA laut russ. org. Datenblatt?
600mA laut russ-dt. Buchkopie		 - -
Anodenverlustleistung "kurzzeitig" 600 Watt 600W - -
Anodenverlustleistung dauernd 450 Watt 450W - -
grid_3 (Bremsgitter):
mit Kathode verbunden - - - -
grid_2 (Schirmgitter):
max.Schirmgitterspannung 600 V - - -
max current (average) - 200mA - -
max. Schirmgitterverlustleistung 120 W 120W - -
grid_1 (Steuergitter):
max.Eingangs(Steuergitter)spannung 300 V - - -
max current (average) - 20mA - -
max. Steuergitterverlustleistung 10 W 10W - -
filament:
filament voltage 11.8-13.4 V

12.6 / 12.7V (11.6-13.4V)

-

-
filament current (max. Heizstrom) 10.5A 10.5A (<11A) - -
other:
bias voltage ??? - 138+/-22V ??? - -
max. Arbeitsfrequenz 50 MHz - - -
max. Glasskolbentemperatur 623 K = 350°C 350°C - -
max. Speiseleistung (PEP-input, 12 MHz) 750 Watt - - -
Steilheit 4.5 - 6.5 mA/V 5.5mA/V - -
Durchgriff g2-g1 2.6 - 3.7 % 2.5-4 / 2.6-3.7 - -
Eingangskapazitaet 25 - 32 pF 25-32 pF - -
Ausgangskapazitaet 21 - 25 pF 21-26 pF - -
Grid_1 - Anode - <0.1 pF - -
Grid_1 - Grid_3 - 1-4pF - -
totale Bauhoehe max. 243 mm - - -
Durchmesser max. 120 mm - - -
Output power -

>700W

-

-

Wenn ich die Daten der GU81M richtig deute, habe ich folgende Waermeproduktion:
600W Anode
120W grid 2
10W grid 1
133W Heizung
863W pro Roehre, bei 3 Roehren also 2600W, das sind fast zwei Heizluefter (oder 3 Foehns) was die Waerme angeht!!

Heiztrafo für GU81M:

Einen Neon umbauen (Shunt komplett entfernen, neue Secondary draufwickeln)!
12,7V@10,5A = 133W pro Röhre => bei 3x GU81M also 400W => Vorgabe also 12,7V @ 32A

=> einige Windungen von Installationsdraht (1,5mm2) in parallel
=> bei ca. 4,5A pro Draht (3A/mm2) => ca. 7 Wicklungen a 12,7V in parallel für 32A.

Leerlaufspannung kann höher liegen => Test mit Lastwiderstand 12.7V/32A = 0,4Ohm (400W => Kranwiderstand nehmen!)

Einfacher wäre es, einen (oder 3 einzelne) 12V-Ringkerntrafo zu nehmen und noch ein paar Windungen zusätzlich draufzuwickeln. http://www.pollin.de/shop/shop.php?cf=produkt.php&ts=0&p=NjkzOTc5

For additional information on the geometry look at these two drawings:
Abmessungen Sockel russ. schematic

For additional electrical data on this tube look at these six diagrams (still to be scanned):

[under construction]

[under construction]
averaged anode characteristics
grid_2 voltage 500V		 averaged grid-anode characteristics for grid_2
grid_2 voltage 500V		 averaged grid-anode characteristics for grid_2
grid_2 voltage 600V

[under construction]

[under construction]

 [under construction]
averaged grid-anode characteristics for grid_2
grid_2 voltage 500V		 averaged grid-anode characteristics for grid_2
grid_2 voltage 600V		 averaged characteristics for
-------- anode-grid
- - - - - grid_2
anode voltage 2500V

[under construction]

2) Circuit diagram:

Wie man eine Pentode als Triode betreibt:

I plan to run the tubes in pulsed mode like John Freau does. This will increase arclength with no additional power needed compared to AC or DC driven coils.

3) Photos:

[under construction]

4) Results:

Current state of development:

nothing ;-)
(only some thoughts)

[under construction]

< more coming soon > [under construction]

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